"Vault" Treasure for a Gunslinger (seeking GM input)

[SnowHeart]

So my group is about to arrive at Brinewall castle. I don't expect them to clear it during our next session, but I suppose it's possible they'll stumble across the vault straight away (stranger things have happened at my table). So, I've put together some items for the PCs as if they'd been left there "by destiny" just for them, but the Gunslinger has been a little difficult. I know the vault was used by visitors to the castle, so there is some flexibility there for the GM, but treasure for a gunslinger is going to be an ongoing issue in this AP simply because guns really haven't been incorporated into it. So, I decided to think outside the box and come up with a slightly more, uh, long-term solution. I've put it below in a spoiler box and would really appreciate any input from fellow GM's and those who have experience playing a gunslinger in a campaign.

To my players... stop reading now. Please.

Spoiler:

In short, once the Amatatsu seal is opened and the kami spirit is able to return, I'm going to have it "splinter", with the portion that has been driven chaotic and slightly mad from the last twenty-five years "possess" the gunslinger's masterwork pistol. The gunslinger in our party is Chaotic Neutral, and although I get the sense kami are generally lawful good, I figure I can have this fragment be chaotic good, creating fewer personality conflicts (but still some, with a potential for interesting RP). My idea is that this kami "fragment" is kind of a child or infant; for lack of a better term, an offspring of the family spirit. Its powers start as relatively weak, but progress as the adventure continues. Thus, the player will essentially have an auto-leveling weapon and I'm not going to have to keep placing magic firearms in regions where they probably shouldn't exist. So, that's the concept.

Here's the general build, with Int/Wis/Cha/Ego somewhat abridged:
Name: Thunder of the Celestial Court
Alignment: Chaotic Good
Special Purpose: Defeat/Slay Oni
4th lvl - +1 pistol - Ego=7 - Int/Cha=12, Wis=10, See/Hear 30' - Empathy - Cast Abundant Ammunition (3/day)
6th lvl - senses extend to 60' - also cast Richocet Shot (1/day)
7th lvl - enhancement increases to +2 - Ego is now 9 - add telepathy
8th lvl - Detect special purpose foes within 60'
9th lvl - Int/Cha=14, Wis=11 - Add Bane Weapon against Outsiders (Oni)
10th lvl - Ego=15 - Add Darkvision
11th lvl - enhancement increases to +3
12th lvl - Cast Named Bullet (1/day)
14th lvl - enhancement increases to +4 - Senses increase to 120' - Richocet Shot now 3/day
15th lvl - Int/Cha=16, Wis=13 - Ego=23 - Special Purpose Power: Blessing of Fervor (at will)

Final base value (at 16th level) will be 166100

I was worried it may be overpowered but the base value starts a bit less than the value of what I'm giving to the rest of the party but moving forward pretty much stays at around half of Wealth by Level, which I have felt is appropriate for a PC's primary item.

Any thoughts or feedback would be appreciated. I've never put together something quite like this, so I'm not as confident about this as I'd like to be.

[SnowHeart]

So, no thoughts whatsoever? Okay. *meekly goes back into his hole to cuddle with his blankie* ;-)

[Kaushal Avan Spellfire]

It looks pretty good from here, although I'm not entirely certain what cumulative enhancement bonus characters of 15th level should usual have on their weapons. I would say you might want to think about adding other weapon abilities other than Evil Outsider Bane/ Native Outsider Bane, such as Holy, but the additional abilities seem to make that unnecessary.
If you have access to Legacy of Fire, I'd compare it to the weapon "Tempest," which was a similar concept: A magical weapon that grew more powerful as the players advanced.

[AmosTrask32]

You are being extraordinarily generous.

spoiler:

In book 2, the group gets a intelligent blade that is made for killing Oni, the castle includes several caches of items such as evil outsider bane arrows, flaming arrows and the like. The trend continues in every edition of the adventure so far, filling the group's coffers with legendary named weapons that destroy Oni. If you plan on adding to that stockpile, I strongly recommend you rebalance basically every encounter in the game. IIRC, that chest should contain 9,000 gp worth of treasure total to be divided between the characters. The group should have found plenty of treasure so far without needing to increase that value. I believe the purpose of the chest is to make them feel destined, NOT to serve as a huge treasure pile.

My suggestions for some level-appropriate gunslinger loot that makes them feel destined:

-A gold dragonscale powder horn with enchanted gunpowder from distant Tian Xia (enough to say, make 50 shots '+1' same value as a +1 weapon, and should give him magic ammo until they have time and money to permanently enchant the gun)

-If he's a long-range gunslinger, maybe some Eyes of the Eagle for sniping

-If he's in melee a lot, maybe some light Tien armor in the style of a bodyguard of house Amatatsu, make it +1 and mithril if he's extraordinarily dextrous.

-Consumables are fantastic, so Elixirs of Hiding, Vision, or the like could help a skill-based gunslinger, and finding a "utility belt" of potions and elixirs can make a one-trick pony feel much more useful.

[SnowHeart]

Thanks guys. Appreciate the feedback. It's a good point about the Oni/Evil outsider-bane weapons that come later (right now I can only think of the outsider bane arrows and, of course, the "sword" in NoFS), but it also seems a bit unfair to leave the gunslinger out of that equation. I'm also following some of the trends in the Brinewall GM thread about increasing the value of the treasure in the vault (the item's base value at the starting point is only 5500). I don't disagree with AmosTrask's point, it is more than is stated in the AP and has a potential for unbalancing things in the short-term, but I think even the writer said he would give his players more than an aggregate value of 9k. (Also, keep in mind a +1 weapon only has a value of 2000gp+mwk weapon cost. This isn't very different from that as a starting point, with the only caveats being (a) it's a pistol and (b) the one spell per day, which really just helps simplify black powder and bullet management -- I'm going to say it doesn't apply to alchemical cartridges.)

That approach may leave them a bit overpowered for a while, but they're an unorthodox party and almost every fight I've thrown at them has been a potential TPK -- lots of fun and challenge but I think they've earned a little reward for coming through so well. That said, long-term I keep coming back to AmosTrask's thoughts on the Oni-bane aspect, how that could result in an overpowered party in combination with the sword/arrows/etc, and I'm rethinking it.

Maybe there's a different special purpose/bane I could give it? Protect the Amatatsu legacy/heir/throne (would take some careful GMing to make sure that doesn't wind up applying to every single fight)?